(1) Field of the Invention
The present invention relates to a synchronous regulation for the turn-on and turn-off phase angles of the sine waveform voltage output by an AC power source, which is a novel regulation mode capable of synchronously regulating the turn-on and turn-off phase angles that breaks through the conventional regulation mode of either regulating the trigger phase angle or regulating the turn-off phase angle, and especially provided with a feature of regulating both of the turn-on and turn-off phase angles with the same phase angle, so that the sine waveform voltage of the AC power source can be kept to output in symmetrical waveforms within the range in which the turn-on and turn-off phase angles being synchronously regulated; the synchronous regulation circuit for turn-on and turn-off phase angle of the AC voltage, provided by the present invention, can be applied to regulate the voltage output by a single-phase AC power source or a multiphase AC power source, for supplying power with stable voltage to a load, or for regulating the output current to the load.
(2) Description of the Prior Art
The conventional regulation method for an AC power source is amplitude modulation (as shown in FIG. 1), and till now, the control means for phase angle is to either regulate the trigger phase angle (as shown in FIG. 2), or regulate the turn-off phase angle (as shown in FIG. 3), thereby the application is limited.